Schade 1987.

Methods	Cross‐over randomised controlled clinical trial Randomisation ratio: 1:1 Superiority design
Participants	Inclusion criteria: people with type 2 diabetes on insulin therapy (≥ 28 IU/day ≥ 3 months), C‐peptide‐positive on stimulation of endogenous insulin secretion (OGTT) Exclusion criteria: hepatic or renal disease or other major diseases that might impair participation, use of sulphonylurea or other drugs that alter glucose control within 1 month of the study Diagnostic criteria: NDDG
Interventions	Number of study centres: > 1? Treatment before study: 55.4 (6.0) IU/day (insulin regimen: 10/16 twice daily) Titration period: 4 weeks (washout)
Outcomes	Primary outcome(s) (as stated in the publication): OGTT, insulin‐ C‐peptide, fasting blood glucose, HbA1c, ery‐glu binding capacity, compliance, insulin dose, weight
Study details	Total study duration: 32 weeks Run‐in period: 4 weeks Study terminated early (for benefit/because of adverse events): no
Publication details	Language of publication: English Funding source: Upjohn, NIH Publication status: peer‐reviewed journal
Stated aim of study	Quote from publication: "To examine the potential beneficial effect of the addition of a second‐generation sulphonylurea to insulin therapy for poorly controlled type 2 diabetes."
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote from publication: "The order of the two treatment regimens was randomised..." Comment: not possible to judge whether the sequence generation was adequate
Allocation concealment (selection bias)	Unclear risk	Comment: not possible to judge whether the allocation to the intervention and control group was concealed
Blinding of participants and personnel (performance bias) Adverse events	Low risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period."
Blinding of participants and personnel (performance bias) HbA1c, FPG, lipids	Low risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period."
Blinding of participants and personnel (performance bias) Insulin dose	Low risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period."
Blinding of outcome assessment (detection bias) Adverse events	Unclear risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period." Comment: unclear if "end of the study" meant the end of the treatment period or after outcome analysis
Blinding of outcome assessment (detection bias) HbA1c, FPG, lipids	Unclear risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period." Comment: unclear if "end of the study" meant the end of the treatment period or after outcome analysis
Blinding of outcome assessment (detection bias) Insulin dose	Unclear risk	Quote from publication: "...neither the patient nor the investigators knew until the completion of the study which treatment regimen the patients were receiving during each 16‐weeks period." Comment: unclear if "end of the study" meant the end of the treatment period or after outcome analysis
Incomplete outcome data (attrition bias) Adverse events	Low risk	Comment: data on weight gain were collected and reported
Incomplete outcome data (attrition bias) HbA1c, FPG, lipids	Low risk	Comment: outcome data were collected and reported
Incomplete outcome data (attrition bias) Insulin dose	Low risk	Comment: data on insulin dose were collected and reported
Selective reporting (reporting bias)	Low risk	Comment: all outcomes of interest were reported
Other bias	Unclear risk	Comment: funded by a pharmaceutical company